The present invention relates to a method and system for device detection in medical images, and more particularly, to detection of a three-dimensional (3D) device, such as a pigtail catheter, in two-dimensional (2D) medical images.
During surgical interventions, catheters are typically inserted into a patient's vessels and guided to, or placed at, a specific position. The automatic detection of such catheters can provide aid to the surgeon. For example, the automatic detection of such catheters can be used for improved visualization or motion compensation for the image-guided procedures.
The projection of 3D device onto a 2D image plane can cause shape variation of medical device. The shape of device on the 2D projection plan depends on the projection angle, and also is affected by continuous body motion.
In the case of transcatheter aortic valve implantation (TAVI), the silhouette of an extracted aorta model can be overlaid on a 2D fluoroscopic video sequence, to visually aid the physician in the placement of the artificial valve. However, since the actual position of the aorta is highly influenced by cardiac and respiratory motion, a mere overlay may not be sufficient. During a TAVI intervention, an agent-injecting pigtail catheter is typically inserted into the aorta. This pigtail catheter is typically inserted into a valve pocket during the intervention, and therefore follows the motion of the aorta. By successfully detecting and tracking the pigtail catheter in the intra-operative fluoroscopic images, it is possible to compensate the motion of the aorta and correctly project the 3D model of the aorta onto its position in each 2D image, thus providing visualization of the aorta without contrast injection.
The tip of the pigtail catheter has an appearance that can vary according to the projection angle of the fluoroscopic image sequence. The appearance of the pigtail catheter tip is also radically altered when contrast agent is injected. Furthermore, during surgical interventions, a number of other devices may also be visible in the proximal area of the pigtail catheter, causing frequent occlusion and clutter. Due to the large inter-class variation in the shape and appearance of the pigtail catheter, as well as low image quality and occlusion and clutter, real-time detection of the pigtail catheter tip can be a very challenging task.